Aluminum Crack Inspection and Repair Examples

7/28/2019 Aluminum Crack Inspection and Repair Examples

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Aluminum Crack RepairAluminum Crack Repair

WithoutWithout WeldingWelding


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TopicsTopics

Crack detection/inspection Metal stitching

Threaded hole repair


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Crack DetectionCrack Detection

Visual Pressure testing

Dye-penetrant


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VisualVisual

Practiced by many asthe only way of

finding cracks.

You wouldnt inspectcast iron this way.

Inconclusive.

You cannot find the

ends of the crack.


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After DyeAfter Dye--Penetrant InspectionPenetrant Inspection


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Pressure TestingPressure Testing

Only shows crackthat leak.

Helps determine

the extent of therepair needed.

Must be done

following any

repair.


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DyeDye--PenetrantPenetrant

Cleaner

Penetrant

Developer


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CleanerCleaner

Do not use to cleanthe test area.

Do not spray

directly on the testarea.

Spray only on a dry

shop towel or other

clean cloth.


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PenetrantPenetrant Use small amount.

Can be applied withbrush.

Messy, difficult toremove.

You must wipe as

much as possible offbefore applying thedeveloper.


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Applying Penetrant With aApplying Penetrant With a

BrushBrush


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DeveloperDeveloper

Test area must bewiped clean ofpenetrant byapplying cleaner tothe cloth beforeapplying developer.

Apply developer asdry as possible. Usecompressed air tospeed drying process.


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Step by step procedure

1


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Step by step procedure

2Wait 5 minutes


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Apply cleaner to clean cloth

3


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Wipe off all visible penetrant

4


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Keep cleaning until all

penetrant is gone

5


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Spray on developer very dry

6


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Use compressed air to

accelerate drying

7


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Wait 1 minute before

inspecting

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Metal StitchingMetal Stitching

oror

Cold RepairCold Repair


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ObjectiveObjective

1. Stop leaks

2. Prevent crack propagation

3. Structural integrity

4. Prevent seats from coming out

5. Remove the crack for cosmetic reasons

6. $$$


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TwoTwo TypesTypes

ofofStitching PinsStitching Pins


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StandardStandard Threaded PinsThreaded Pins

Straight thread L Seriespins

Seal by interference fit ofthe threads

Exert spreading pressure

For sealing, seat retentionand crack removal


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CASTMASTERCASTMASTER Threaded PinsThreaded Pins

Spiralhook threads

Radial drawing forccreates structural

integrity Not used for seatretention

Seal leaks Prevent crack

propagation


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Working With AluminumWorking With Aluminum

Requires cutting fluid for drilling and tapping. Galls easily.

Cuts easier than cast iron.

Very easy to oversize and egg-shape drilled holes.

Aluminum stitching pins are required in

combustion chambers of cylinder heads. Steel pins can be used for structural repairs.


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Cylinder HeadsCylinder Heads

Many cracks can be repaired withoutremoving the seat inserts by using L Series

pins. Do not drill into water if the crack does not

leak. When the crack does leak you must install

pins under and behind the seat to stop the

leak.


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Cylinder HeadsCylinder Heads

Only when the crack goes between two seats

can you use a steel pin.

Cracks on the top side and between

cylinders on the deck surface require

CASTMASTER pins for structuralintegrity.


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Ford Escort cylinder headFord Escort cylinder head


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Crack over exhaust portCrack over exhaust port


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Install C1 CASTMASTERInstall C1 CASTMASTER

stitching pinstitching pin


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Install L Series pinInstall L Series pin

intersecting the seat insertintersecting the seat insert


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Install L Series pin into theInstall L Series pin into the

floor of the water holefloor of the water hole


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Finished repairFinished repair


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Stitching Pin SelectionStitching Pin Selection

Most aluminum cyl heads have fairly thin walls so

you should use L4 pins that have very fine threads

The fine threads also work well when tapping into

the hard seat insert. L4 pins will fit in between the seats in most cases.

Larger diameter pins are used when the casting is

thicker.


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Structural RepairStructural Repair

UsingUsingCASTMASTERCASTMASTER

Stitching PinsStitching Pins


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InspectionInspection


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Drill the first holeDrill the first hole


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Spotface the holeSpotface the hole


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Apply tapping fluidApply tapping fluid


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Tap the holeTap the hole


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Apply thread sealantApply thread sealant

I t ll C1A l iI t ll C1A l i


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Install a C1A aluminumInstall a C1A aluminum

CASTMASTER stitching pinCASTMASTER stitching pin

Th h d f th i t i t ffTh h d f th i t i t ff


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The head of the pin twists offThe head of the pin twists off

when tightwhen tight

G i d ff h ldG i d ff h ld


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Grind off excess shoulderGrind off excess shoulder

close to flushclose to flush

D ill th t i li htlD ill th t i li htl


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Drill so that pins slightlyDrill so that pins slightly

overlapoverlap

C ti i t lli i tilContinue installing pins until


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Continue installing pins untilContinue installing pins until

the crack is removedthe crack is removed

G i d i fl h dGrind pins flush and peen


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Grind pins flush and peenGrind pins flush and peen

lightly with a needle scalerlightly with a needle scaler


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Completed RepairCompleted Repair


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Pressure test to 40 PSIPressure test to 40 PSI


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Advantages Over WeldingAdvantages Over Welding

Faster Very cost effective

No distortion

Will not anneal the surrounding aluminum


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Advantages of Welding OverAdvantages of Welding Over

StitchingStitching

Welding can repair erosion and electrolysisdamage.

Welding can add reinforcement by adding

material to weak areas such as around headbolt holes.

Welding can replace missing pieces. Welding can build up bearing bores.

OthOther Al i C tiAluminum Castings


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OtherOtherAluminum CastingsAluminum Castings

That Can Be Repaired byThat Can Be Repaired byStitchingStitching

9Aluminum oil pans for Cummins, Cat

and other diesel engines

9Water cooled marine manifolds

9Bell housings and transmission cases

9Engine blocks and intake manifold


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LOCK-N-STITCH Inc.1015 S. Soderquist Rd

Turlock, CA 95380

800-736-8261209-632-2345

www.locknstitch.com

Email for technical support

[email protected]

Documents

Aluminum Crack Inspection and Repair Examples